Intercommunication apparatus



Nov. 10, 1953 A. LlBx-:RMAN 2,658,947

INTERCOMMUNICATION APPARATUS Filed Nov. 25. 1949 2 Sheets-sheet l @l f 1225.24 fzfi z z Nov. 1o, 1953 A. LIBERMAN 2,658,947

INTERCOMMUNICATION APPARATUS Filed Nov. 25. 1949 v 2 Sheets-Sheet 2 BOX @fz/@Zig friese Patented Nov. l 10, r1953 UNITED STATES PATENT OFFICE INTERCOMMUNICATION APPARATUS Arie Liberman, Chicago, Ill.

Application November 25, 1949, Serial No. 129,411

6 Claims. (Cl. 179-1) This invention relates to intercommunication apparatus, and more particularly to intercommunication apparatus having one or more stations provided with novel selector means for selecting between various types of operation of each of a plurality of stations in the system.

One feature of this invention is that it provides novel selector means for selecting between types of operation of stations; another feature of the invention is that said selector means have at least one first terminal for one type of operation, at least one second terminal for another type of operation, and a plurality of intermediate terminals for connection to either said first or second terminals; a further feature of the invention is that it provides a plurality of station selector arrangements including first switches each having at least one contact connected to a cable leading to other stations and at least one contact removably connected to one of said intermediate terminals, and secondary switch means having different contacts connected to each of said first and second terminals; an additional feature of the invention is that the first and second terminals of said station selector means each comprises a group of terminals, each group including a plurality of terminals for connecting individual stations for either type of operation and including at least two terminals each for connecting a plurality of stations as a unit for one type of operation and at least two terminals each for connecting a plurality of stations as a unit for another type of operation; and still another feature of the invention is that the selector means has at least one pair of terminals having a readily removable jumper connection therebetween for determining the type of operation of the station with which the selector is associated.

Other features and advantages of the invention will be apparent from the following specification and from the drawings, in which:

Fig. 1 is-a block diagram of an intercommunication system showing four stations;

Fig. 2 is a front elevational view of one of the stations in Fig. 1;

Fig. 3 is an end elevational view of the station of Fig. 2; and v Fig. 4 is a schematic wiring diagram of one of theA stations of Fig. 1.

An intercommunication system of the character illustrating an embodiment of this invention comprises a plurality of stations connected` to each other to provide intercommunication therebetween. The term local station is herein employed merely to designate the particular station the operation of which isbeing disclosed', and the term distant station is herein ernployed merely to designate other stationsr in the system, without regard to the actual location of these other stations. The stations may be socalled master stations including an amplifier, or may be so-called staff stations which have no amplifier, but merely comprise a translating device (as a speaker-microphone) and switching means. A master station may communicate with a staff station or another master station, the voice of the operator of the master station being amplified at his local station and then being connected to a desired distant station through a switching system as will be herein disclosed. However, a staff station hasvno amplifier and generally may communicate (or at least originate a conversation) only with master stations (normally few in number), to which the staff station is connected, the amplifier in the master station being utilized to render lthe signal which originates at the staff station strong enough to operate a speaker properly.

In certain intercommunicating systems, means are provided wherein certain stations may be private-i. e., a station may be connected or arranged in such manner that sounds at that location can be heard only after that person moves his talk-listen switch to talk position. Other stations in the same system may be so arranged, if desired, that they are nonprivate i. e., any master station making connection to that station through operating the appropriate connector switch may hear anything at the nonprivate location without any act by the person there. In the system disclosed herein, a staff station which is connected for non-private ope.- eration may originate a call only with the master station or stations with which it is connected, but any other master station in the system can ca ll the staff station and the staff station can reply without operating the talk-listen switch; while a staff station connectedfor private operation can converse with onlyr thegmaster stationor stations to which it is connected, and the talklisten switch at the staff station must be operated to talk to said master station or stations, an arrangement may also be made wherein any master station in the system can call any private staff station only for paging purposes, but the staff station cannot reply to the master station unless it is connected thereto.

Each intercommunication system may, by my improved arrangement, have a different hook-up from other systems; and this hook-up may be varied from time to time after the system is installed. For example, a system may include only a few stations as illustrated in Fig. 1 or it may include as many as forty or more stations; and in any given installation the number of master stations and staff stations may vary, and the number of stations connected for private operation or for non-private operation may vary. Despite all these variations whichare possible in each different system, it is desirable to be able s to manufacture systems on a mass production basis wherein each item or unit is standardized.

In the past it has been impossible to manufacture' Y such systems by mass production methods and at the same time take into account all the variations required for each individual system.

I have devised and am herein disclosingand claiming an intercommunication system having means associated with at least one station for selecting other stations including selector means for selecting between two types of operation of said other stations, said selector means having a group of terminals for connection for the type of operation, a group of terminals for connection for another type of operation, and a plurality of intermediate terminals for connection to either iirst or second groups. With my improved apparatus, readily removable means may be provided for interconnecting the intermediate terminals with either of the groups to determine the type of operation of each station, and intercommunication systems may be manufactured on a mass production basis and yet readily be converted to cover all various types of operation either at the time of installation or after the system has been installed in the event the conditions under which the system is used change.

In using the words intermediate terminals I do not intend to limit the physical location of said terminals, and these words should be construed to mean that the terminals are intermediate" in the sense that they may be connected to either one of the groups of terminals which determine the type ofoperation.

The selector means includes at least one pair of terminals having a readily removable jumper connection therebetween for determining the type of operation of the station with which the selector means is connected. Y

Referring tothe drawings, Fig. 1 shows 'a simple intercommunication system having 'four stations therein, -e'ach station having a different number forconvenience in designation. It will be understood Athat the inventionA is applicable to much more compex systems having `any desired number of stations therein. In Fig. 1 `three `master stations fl-0, 'Il and I2 vare shown. 'Each master station has associated 'therewith a junction box No, AIla, and I2a respectively, and each master station is Aconnected to its junctionbox by va cable b, II'b, and |217 respectively. .The junction boxes jare 'connected ytogether byv cables I3 and I4, anda staff 'stationf is connected .to station "N by a 'cable I6. In this system each master station may 'converse with each other master station, while the staff station may originate a conversation only with master station I0. If the stad station is connected for private operation, it may converse only with the master station I0, although master stations II and I2 may talk to staff station I5 if the stati station selector switch is pushed at the master station. If staff station I5 is connected for non-private operation any master station in the system can talk to the staff station and persons at the staff station can answer from a distance without operating any controls. In other words, the microphone at the staff station may be connected to any master station at the will of the operator of the master station.

One of the master stations, as for example, master station I0, is shown in Figs. 2 and 3. This station will be designated herein as a local station merely because it is the station the operation of which will be described, and the other stations in the system will be designated herein as distant stations. The station comprises a cabinet I'I housing an amplifier, speaker and microphone, switching arrangement, and means for selecting the type of operation of other stations. On the face of the cabinet is a control knob I8 which may be a combination on-oi switch and volume control knob as is common in the art. A switch bar I9 operates a talk-listen switch more fully disclosed in Fig. 3, and across the face of the cabinet is a row of twelve pushbuttons 2|lf3l. These pushbuttons operate the station selector switches and while illustrated as pushbuttons, obviously other types of switches, such as rotary selector switches, can be utilized.

While only four stations are illustrated in the simple diagram of Fig. 1, it will be understood that generally more stations are incorporated in such a system. 'I'he circuit of Fig. 3 illustrates a 20-station system, and the same cabinet and pushbutton arrangement may be utilized for forty or more stations, as more fully disclosed in my application for Switching System, Serial No. 126,327, iiled November 9, 1949. In the event no more than twelve stations are in the system, each pushbutton 2li-3| may select one of those stations. In the event more than twelve stations are in the system pushbuttons 30 and 3| may select groups of stations, and each pushbutton 20-29 may be connected to select one station from each group. For example, in my above mentioned application wherein a forty.- station system is disclosed, pushbutton 20 might select any one of stations No. I, II, 2| and 3| and, if pushbutton 20 alone is pushed, station is selected. Pushbutton 30 may "add 10 so that in the event pushbutton 20 and 3|! are both operated station I| would be selected; pushbutton 3| may add 2 0 so that in the event pushE buttons 20 and 3| are both operated station 2| would be selected; and pushbuttons 30 and 3| together may "add 30 ,so that in the event pushbuttons 2.0, 30 and 3| Aare all operated together station 3| would be selected.

In Fig: 4 `.the circuit of master station In is shown; .Cable I 0b connects junction box Inc with the master Stat-ion; cable I3 connects junction box |0a with other junction boxes in the system, and `cable |16 vconnects Ajunction box Illa with staff station I5 as shown in Fig. l.

Within the cabinet of master station |.0 is an amplifier designated generally at A, which comprises a conventional audio amplier; a transducer designated generally at B, which may comprise .a conventional .Speaker-microphone; a

talk-listenswitch and its associated circuits designated generally at C; a plurality of station selector switches designated generally-at D; secondary switch means designated generally at E; and selector means for selecting between two different types of operation, this selector means being designated generally at F.

The talk-listen switch C comprises six singlepole, double-throw switches 35, 36, 31, 38,Y 39 and 40 and two single-pole, single-throw switches III and 42, all of these being ganged for operation by the talk-listen pushbutton I9. `The tallilisten switch is shown in talk position. If the switch is operated by push-bar I9 to its other position it will be in listen position.

While a system incorporating forty or more stations may be controlled from the twelve pushbuttons -3I of Fig. 2, for simplicity vI have shown a 20-station system in the wiring diagram of Fig. 4. Pushbutton '20 controls two ganged double-pole, single-throw switches 29a and. 20h; pushbutton 2| controls two'ganged double-pole, single-throw switches 2 Ia andY 2 Ib. Pushbuttons 23-21 control similar ganged switches not shown for simplicity. Pushbutton 28 controlsv two' and 30h comprise an add 10 switch. In a 20- station system as illustrated, pushbutto'n 3l is not needed. When in the position shown, any one of stations numbered I-I may be selected by any one of the pushbuttons 20-29, and if the pushbutton 3i) is operated along with one of pushbutif tons 20-29, it moves switches 30a and 3th to the position other than that shown and under these conditions any one of stations numbered II-ZI! may be selected by any one of pushbuttons 2U-29. In the event thirty stations were in the system, another horizontal row of station selector switches would be added, and pushbutton 3l would be employed to operate switches similar to those shown at 30a and 30h, being an add 20 switch. In the event that forty stations were in the system, four horizontal rows of station selector switches would be provided and the switch 30 would comprise four double-pole, double-throw switches, while another switch would be provided for operation by pushbutton 3I.

The selector means F for selecting between the two types of operation comprises a mounting board 43 having a plurality of horizontally eX- tending rows of terminals. It will be understood that each of the terminals is of the type adapted for ready connection and ready removal of a lead. The top row designated Y includes at one end a terminal labeled MI-IIJ and at the other end a terminal labeled SI-I0, and ive terminals extend in a row between these two end terminals, the i'lve terminals being labeled I, 2, 3, d and 5 respectively. The second row of terminals designated Z is similar, these two rows constituting a like terminal arrangement for use in a two-wire system.

In like manner the third and fourth rows of terminals are similar to each other, row Y including seven terminals designated respectively as MI-I0, I5-I0, MI I-2IJ, I I-20, SI I-20, L and L. The terminals MI-I in the sul `third and fourth rows are provided merelyfor convenience in making connections and are interconnected with terminals MI-I0 in the respective rst and second rows. If desired, similar duplicate terminals SI-I0 may be provided in the third and fourth rows of terminals. The terminals labeled M comprise a group for private operation; the terminals labeled S comprise a group for non-private operation, and the terminals designated only by number comprise a plurality of intermediate terminals for connection to eitherof said groups. The two pairs of L terminals are utilized to determine the type of operation ofthe station with which the selector means is associated.

' In the system illustrated, a station is selected by one of switches 20a-29a, which are connected for private operation' or` by switches 20h-29h which are connected for non-private operation. Each station selector .twitch has contacts (the lower contacts as shown) connected to the cable lob which extends 'between the respective switches and the junction box, and other contacts removably connected to certain of the intermediate terminals. The left upper contact of switch 20a. is connected by a lead 44 to intermediate terminal I in row Y (hereafter designated as terminal YI) and the upper right contact of this switch is connected by a lead 45 to intermediate terminal I in row Z (hereafter'designatedY as terminal ZI). Similarly leads 46 and i1 connect the upper contacts of switch'ZIa to respective terminals, Y2 and Z2. The upper contacts of switches 28a and 29a are connected to respective terminals YB-I I) and ZG-II] by leads 48 and 49.

The upper contacts of switches 2Gb and 2lb areconnected to respective terminalsYI I-'K20 and ZI I-20 by leads 50 and 5I, and the upper contacts of switches28b and 29h are connected into this circuit by branch leads'llo: and Bla.

Terminals YI, Y2, YS, YII and YE and terminals ZI, Z2, Z3, Z4 and Z5 comprise a plurality of terminals each for connecting an individual station for either type of operation. In the circuit shown, terminals YI, Y2, Y3, YlI and YE are shown as interconnected with terminal YMI-III and terminals ZI, Z2, Z3, Z4 and Z5 are shown as interconnected with terminal ZMI-IIJ. Thus stations I-5 are connected individually for private operation. If it were desired to make stanecessary to disconnect terminals Y2 and Z2 rel.spectively from terminals YMI-II) and ZMI-II'I and connect `them to terminals YSL-Iii and ZSI-III.

lOn4 theother hand terminals YB-IO and Zi-IIIV are for connecting a plurality of stations as a unit for eithertype of operation. As shown, these termin-als are connected for private operation. If` it were `desired to connect stations I-Ill as a unit for non-private operation, terminals YB-Iil `andZ'-Ill would be disconnected respectively from' YMI-III and ZMI-Il and would be connected to terminals YSI-Ill and ZSI-Ill. In the same manner stations II-Zlly are shownl as connected as a unit for non-private operation becauseterminals YII-2I'iv and ZII-2Il are connected respectively to terminals YSII-ZIB and ZSII-Zii. If desired these connections may readily be changed to connect staf tions I I-2II as a unit for private operation'. Consequently, in the manufacture of these intercommunication systems A a standard arrangement may be provided and yet any arrangement may be made'either at the time of installation or at any time after installation for connecting any ifirnber of' stations for private operation or fr l10n-private Oper-ation s desired. Frtherniore, an important vfeature is' that any .given station may be private to some of the other stations in `the system andl non-private to others. It is not necessary that any given station be connected for the same type of operation with all other stations in the system. In other words, while station No. 4 is illustrated as being connected for private operation with the local station being described, station No. 4 may be connected with other distant stations for non-private operation if desired.

` The upper contacts of switch BUa' control all stations i-ID which are connected for private operation insofar as the local station being described is concerned, these upper contacts being connected to the respective terminals' YMl-Ill and ZM ||0 by leads 54 and 55. The lower contacts of switch 30a control all those stations II-'ZG which are connected for Yprit/'ate operation insofar as Athe local station being described is concerned, these lower contacts lbeing connected to the respective terminals YMII-ZIJ and ZM! l`20 by leads 56 and 51.

The upper contacts of switch 39h control all those stations |-l0 which are connected for non-private operation insofar as the local station being described is concerned, these upper contacts being connected to the respective terminals YSl-Hl and ZS'l-IU by leads 58 and 55?. The lower contacts of switch 301) control all those Stations H-ZD which are connected for non-private operation insofar as the local station being described is concerned, these lower contacts being connected to the respective terminals YSI and ZSI l-ZD by leads El) and 6l.

In the operation of the intercommunication system, with the talk-listen switch 'in the position shown the operator of the local station may talk to any distant station by operating the station selector switches. For example, if the operator wishes to talk to station l2, he would push pushbutton v2| thus closing switches 2id and 2lb and would also push pushbutton 3B thus adding l0 and moving switches 30a and h to the position other than that shown so that the movable poles of the switches close with the lower contacts thereof. When the operator speaks into the transducer B the voice waves are-translated into electrical energy and appear across leads 65 and 66 which are -connected with the input of the amplifier A. Lead 65 connects with the movable pole of switch 35, the closed `contact of this switch being connected to the amplier input by lead 61, while lead 65 connects with the movable pole of switch 31, the closed contact of this switch being connected with the other ampliiier input terminal by a. lead V68. The audio ampliiier A ampliies the voice waves and connects them through closed switch '2lb to the cable lb. In the junction box Illa connection is made to station I2. The connection between the ampliiier output and the selector switches is .as follows: from one terminal of the amplifier through a lead E9, switch 39, a lead 10, switch 38, lead 1|, and lead 12 to the movable pole of switch 30b which `is now closed with the lower contact of said switch. Lead '6| connects the lower contact of said switch with terminal ZSI |20, this terminal being interconnected with terminal Ztl-20 which 'is 'con- 8. nected to closed switch 2lb for station f2 'by lead 5|. Y

The other output terminal of the ampliiierv vis connected by a lead 14 to the movable pole of switch 4U. A lead 15 connects the closed con-- tact of switch 40 with one contact of switch 36, and a lead 16 connects the movable pole of switch 36 with the other movable pole of switch 30h. The other lower stationary contact of switch 30h is connected by the lead BU to terminal YSI l-Zll which is interconnected with terminal YI |-20, this latter terminal being connected by lead 50 to the other contact of switch 2lb'.

When the operator of the local station wishes to listen to the distant station, interconnections in the junction box Illa bring the signal in to the local station through leads 11 and 18 which are connected across .a volume control resistor v19. One end of the volume control resistor is connected vto a contact of switch 31 by a lead 80, and this contact (when the switch is in listen position) is connected 'to the speaker through lead 6-6. The movable slider of the volume control is connected to one contact of switch 35 by a lead 8l, and this contact is connected to the speaker through lead `t5. Inasmuch as the incoming signal was already amplified at the distant master station, no further amplification is normally required at the local station. However, when the local station conversos with the stai station, the incoming signal from the stair .station has not earlier been amplied and must be amplified at the local station. Incoming signals from staff stations are connected in the junction box into leads 83 and 84 which connect with respective switches 4| and 42, these switches also being closed when in listen position. A branch lead 11a connects the movable pole of switch 4I with lead 1l, and this lead is connected to the amplier input through switch 38 and a branch lead 68a which connects with lead v68. Switch 42 is connected to lead 16 Iby a branch lead 16a and connection is made to the amplier input through leads 16a, 1:5, switch 3S, branch lead r61a and lead 4l1.

With the talk-listen switch in listen position, the amplier output terminals are connected with the speaker so long as jumpers are connected between the terminals of each pair des'- ignated LL on the selector F. The upper amplifier output `terminal is connected to the speaker through lead 59, switch 39 and a lead 35 which connects one contact of switch 39 with one of the L terminals of the selector Ameans'. The two L terminals are connected by `a jumper and a lead 85 connects the other L terminal with one end of the volume control resistor 19, connection to the speaker being made through lead 8G, switch 31 and lead 66. The lower amplier output terminal is connected through lead 14, switch 40 and a lead 81, a jumper between the other L terminals and the lead 88 which connects with the other end of the volume control resistor 19 through the lead 11. Connection to the speaker is completed through lead 8l switch 35 and lead 65. In the event LL jumpers are removed, the amplifier output is no longer connected to the speaker and the station can be made non-private as to other stations so connected.

While I have shown and described certain embodiments of my invention, it is to be understood that 'it is capable of many modifications. Changes, therefore, in the construction vand arrangement may be made without departing from the spirit and scope' of the invention as disclosed in the appendedlclaims.

I claim:

1.'In an intercommunication system having a plurality of stations and cable means interconnecting said stations to provide for communication therebetween, means in at least one station for selecting other stations, comprising: means for selecting between private and nonprivate'operation of said other stations, including a circuit in said one station having at least one first terminal for private operation, a circuit in said one station having at least one second terminal for non-private operation, a plurality of intermediate terminals each adapted to be connected to at least one of said other stations and readily removable leads interconnecting each of said intermediate terminals with either said first or said second terminals to determine whether each of said other stations shall be private or non-private with regard to said one station; and a plurality of station selector switches each having at least one contact connected to a portion of sai-d cable means and at least one other contact connected to one of said intermediate terminals, to select the other station with which said one station will communicate.

2. In an intercommunication system having a plurality of stations and cable means interconnecting said stations to provide for communication therebetween, means in at least one station for selecting other stations, comprising: means for selecting between private and nonprivate operation of said other stations, including at least two first terminals for private operation, at least two second terminals for nonprivate operation, a plurality of intermediate terminals adapted to be connected to said other stations and readily removable leads interconnecting each of said intermediate terminals with one of said first or second terminals to determine whether each of said other stations shall be private or non-private with regard to said one station; two groups of station selector switches, each switch in one group being ganged with a switch in the other group and each switch having at least one contact connected to a portion of said cable means and at least one other contact connected to one of said intermediate terminals, the intermediate terminals connected to the switches of one group being connected only to one of said first or second terminals and the intermediate terminals connected to the switches of the other group being connected only to the other of said first or second terminals; secondary switch means comprising a double throw switch having at least two sections, each section having two fixed contactsand an element movable therebetween, the fixed contacts of yone section being connected with said first terminals` and the fixed contacts of the other section being connected with said second terminals; means connecting the movable element of said one section with said one station; and means connecting said movable element of said other section with said one station.

3. Apparatus of the character described in claim 2 wherein said plurality of intermediate terminals includes a terminal for connecting ka plurality of stations as a unit for a given type of operation.

4. In a two wire intercommunication system having more than two stations and cable means interconnecting said stations to provide for communication therebetween, means in at least one 10 ofY said stations for selecting `other of said stations, comprising: means for selecting between private and non-private operation oi said other stations with regard to said one station, including at least one pair of rst terminals for private operation, at least one pair of second terminals for non-private operation, a plurality of pair of intermediate terminals each pair vadapted to be connected to the two wires from at least one of said other stations and pairs of readily removable leads interconnecting each pair of intermediate-terminals with one or the other of thepairs of said iirst or second terminals; a plurality of double-pole, single-throw station selector switches, each switch having one pair of contacts connected to said rcable means and the other pair of contacts connected to a pair of said intermediate terminals, to select the other station with which said one station will communicate; means connecting said private operation terminals to said one station; and means connecting said non-private operation terminals to said one station.

5. In a two wire intercommunication system having more than two stations and cable means interconnecting said stations to provide for communication therebetween, means in at least one of said stations for selecting other of said stations, comprising: means for selecting between private and non-private operation of said other stations, including at least two pairs of rst terminals for private operation, at least two pairs of second terminals for non-private operation, a plurality of pairs of intermediate terminals adapted to be connected to said other stations and pairs of readily removable leads interconnecting each pair Vof intermediate terminals with one or the other of said pairs of rst or second terminals to determine whether each of said other stations shall be private or non-private with regard to said one station; two groups of doublepole, single-throw station selector switches, each switch in one group being ganged with a switch in the other group, and each switch having a pair of contacts connected to said cable means and the other pair of contacts connected to a pair of said intermediate terminals, to select the other station with which said one station will communicate, the pairs oi? intermediate terminals connected to the switches of one group being connected only to one of the pairs-of the irst or second terminals and the pairs of intermediate terminals connected to the switches of the other group being connected only to the other of the pairs of the first or second terminals; secondary switch means comprising a four section, doublethrow switch, each section having two fixed contacts and an element movable therebetween, theV iixed contacts of two sections being connected with-the pairs of said iirst terminals and the xed contacts of the other two sections being connected with the pairs of said second terminals;

means connecting the movable elements of theV Viirst two sections with said one station; and

means connecting the movable element of said other two sections with said one station.

6. In an intercommunication system having a plurality of stationsand cable means interconnecting said stations to provide for communication therebetween, means in at least one station',V

for Vselecting other stations', comprising: means for` selecting between private and non-private operation oi said other stations, including a circuit in said one station having a connection point, for private operation, a circuit in said one station having a connection point for non-pifivate operation, a plurality of intermediate connection points and means readily removably interconnecting said intermediate connection points with either said private or non-.private connection points to determine Whether each of said other stations shall be private or non-private with regard to said one station; and means for selectively connecting a desired portion of said cable means to said plurality of intermediate connection points to select the other station with which said one station will communicate.

ARIE LIBERMAN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date Thomsen Feb. 7', 1939 Campbell June 13J 1939 Roseby Dec. 1 0, 1940 Goodale et al. Mar. 31, 1942 Campbell Aug. 10,1943 Paust Jan. 2, 1945 

